Passing Data to Views

There are three different ways in which data can be passed to a view by using the ViewDataDictionary, the ViewBag, and strongly typed views.

 

ViewDataDictionary

public ViewResult Show(int id)
{
    var entry = _db.Entries.Find(id);
    bool hasPermission = User.Identity.Name == entry.Name;
    ViewData["hasPermission"] = hasPermission;
    return View(entry);
}

 

In the view, we extract the hasPermission information from ViewData, but we need a cast:

 

<p>
    @{
        bool hasPermission =
        (bool)ViewData["hasPermission"];
    }
</p>

ViewBag

ViewBag provides a way to pass data from the controller to the view, but the ViewBag makes use of the dynamic language features of C# 4. Instead of storing items in a dictionary using a string key, you can simply set properties on the dynamic ViewBag property within your controller:

ViewBag.HasPermission = hasPermission;

<p>
    @if (ViewBag.HasPermission)
 {


 }
</p>

Strongly typed views with a view model

In controller:

public ActionResult Index()
        {
            var mostRecentEntries =
                (from entry in m_guestbookContext.Entries
                 orderby entry.DateAdded descending
                 select entry).Take(20);

            return View(mostRecentEntries.ToList()); // Passed data to view, View method encapsulates setting the ViewData.Model property
        }

In view:

@using Guestbook.Models
@model List<GuestbookEntry>